6 ms·

Origins and History of Unix, 1969-1995 (2003)

147 points by rayascott 9y ago

KasianFranks 9y ago
*NIX, drives most of the world and is the reason why we exist the way we do today. It's also the reason why Google, Apple and other smaller outfits exist today.
- macintux 9y ago
  Agreed mostly, although I imagine VMS would have filled roughly the same ecological niche had UNIX not carried the day. Or maybe that's just optimism that something would have survived Microsoft's onslaught. The days when it looked like Windows was going to rule the world were quite dark.
  - tyingq 9y ago
    That's an interesting path to think about. Minus UNIX, I'm curious where MVS, OS/400, VMS, MPE, DOS/Windows, etc, would have all played out.
    - Taniwha 9y ago
      well VMS still exists .... both as itself and as the underpinnings of WindowsNT (and modern windows)
      - ghaff 9y ago
        Many are still around to some degree. OS/400 is now IBM i. MVS is now z/OS (for IBM mainframes). OpenVMS as you say. Most of the operating systems that were originally written for minicomputers aren't radically different in fundamental design from Unix and Windows NT. My suspicion is that, absent Unix or something that followed a similar historical trajectory, these OSs would have had a longer run as non-legacy products, the landscape would have been even more fractured than it was with the Unix wars, and Windows would have become more dominant in the server space than it eventually became. The question I really don't know the answer to is whether, given the rise of the mainstream Internet, an open source operating system and infrastructure software necessarily would have followed. Or would the world look very very different.
      - bitwize 9y ago
        While it's true that Dave Cutler incorporated many ideas from VMS into Windows NT... they are very different beasts with very different code bases. Not even related in the same way that, say, Unix and Linux are.
    - dredmorbius 9y ago
      VM/CMS (another mainframe variant) may have played a stronger role. It in many aspects resembles Unix, far more than MVS.
      - skissane 9y ago
        What specific features of VM/CMS are you thinking of when you say that? If anything, I would say it is the other way around. The classic MVS filesystem is more hierarchical than the classic CMS filesystem (when I say "classic", I mean ignoring newer innovations such as SFS, BFS, HFS and zFS). The components of MVS dataset names resemble directories, even though they are mostly (but not entirely) just a naming convention. By contrast, the classic CMS filesystem (pre-SFS/BFS) has an essentially flat namespace on each minidisk – its file naming is closer to PC-DOS 1.0 than to Unix. So, even though both filesystems are quite remote from Unix, the MVS filesystem is a little bit closer to Unix's than the CMS filesystem is. Also, if you compare the support for multitasking on MVS to VM/CMS, I think you'll find that MVS is closer to Unix. A single MVS operating system image has multiple address spaces (processes) each containing one or more tasks (threads). By contrast, VM/CMS works by running a single-tasking operating system (CMS) in separate virtual machines on top of a hypervisor (although more recent CMS versions have added "application multitasking" which is roughly equivalent to threads). Although neither is exactly the same as the Unix model of processes and threads, MVS is much closer to Unix than VM/CMS is in this area. Given that, it is actually much easier to implement the Unix process model on top of MVS than on top of CMS, which I suspect is why MVS OpenEdition / z/OS Unix System Services comes with a full-featured fork() implementation (which passes the Unix conformance test suite), while CMS OpenExtensions' fork() isn't really fork() at all, it is actually vfork() pretending to be fork().
        dredmorbius 9y ago
        I've not used CMS, though I have used, long ago, MVS. My understanding is that CMS followed in its genesis and development spirit a bit more of the Unix development mode. It was more popular among (at least some) users, and as I understood it, a bit of an ugly stepchild / embarrassment to IBM, who considered MVS the more buttoned down, business-oriented, product. This is based on some long-ago, hazy, second-hand accounts, mind.
  - pjmlp 9y ago
    The desktop world has hardly changed thanks to the continuous GNU/Linux reboots. http://store.steampowered.com/hwsurvey http://store.steampowered.com/hwsurvey
    - ghaff 9y ago
      For the average person, Linux didn't and doesn't offer any compelling advantages for the desktop and had some potential disadvantages depending upon how it was used. Arguably, there are fewer good reasons to not use Linux any longer, but the desktop OS is increasingly irrelevant to most people anyway. Looking back, it's very unclear to me what commercially viable investments would have changed the overall trajectory of the desktop.
      - pjmlp 9y ago
        On iOS, ChromeOS, Android, the kernel is irrelevant. The fact that they run some variation of UNIX is a pyrrhic victory. Apple and Google can change the kernel to whatever they want, as long as they keep the iOS Kit APIs, Web APIs and Android Java Frameworks. Mostly only those writing device drivers would actually notice the difference. As an example where it is going, the new iOS 11 network APIs are not supported on BSD sockets, and Treble kind of moves Android into a pseudo micro-kernel model.
        spamizbad 9y ago
        This line of thinking doesn't really make any sense. Both Apple and Google had plenty of options to chose from when laying the foundation for their operating system. Ultimately, in both cases, a *nix won out. Allowing BSD sockets inside the iOS Sandbox doesn't mean much of anything. Also, not clear on what Treble means here: Since its adoption in Oreo, Google has be demanding SoC vendors track closer to newer version of the Linux kernel. Source: https://www.xda-developers.com/google-mandating-linux-kernel-versions-android-oreo/ https://www.xda-developers.com/google-mandating-linux-kernel...
        pjmlp 9y ago
  - ghaff 9y ago
    Absent Unix or a class of operating systems coming out of a similar tradition, the operating systems that came out of the minicomputer era (VMS, AOS/VS, OS/400, etc.) would presumably have maintained their roles to some degree absent Unixes displacing them. And it's very hard to see Windows NT not largely winning out in such a world. As you suggest, it was a close thing as it was and a lot of people thought Scott McNealy was tilting at windmills for not buying into Windows inevitability. Of course, that raises the question of what about open source in that world. I'm not sure it was in any sense inevitable that open source would have played out as it did. Although absent widespread open source adoption it is hard to see how the Internet would have grown as it did.
akerro 9y ago
If anyone is interested, I made a catalogue of UNIX-repos that I found online, I setup a gitlab account for all of it, with automated mirroring, here is the link https://gitlab.com/users/UNIX-history/projects https://gitlab.com/users/UNIX-history/projects If you know a repo I don't have here, let me know
- macintux 9y ago
  Not a repo, may be one somewhere though: http://www.nesssoftware.com/home/mwc/source.php http://www.nesssoftware.com/home/mwc/source.php (Considered buying Coherent way back in the day) There is an empty repo by this name in your project so I'm a bit confused whether this one is supposed to be included: https://github.com/dspinellis/unix-history-repo https://github.com/dspinellis/unix-history-repo
  - akerro 9y ago
    Haha gitlab timeouted importing this repo and threw server error 500 on it, I'll do it manually.
  - emmelaich 9y ago
    Diomidis Spinnelis' work is amazing. You can read about it here: https://www2.dmst.aueb.gr/dds/pubs/jrnl/2016-EMPSE-unix-history/html/unix-history.html https://www2.dmst.aueb.gr/dds/pubs/jrnl/2016-EMPSE-unix-hist... (link is from the github README)
- emmelaich 9y ago
  It would be nice to provide a description on that page of where you got each one. For instance, it's not clear whether it has any overlap with the Unix Heritage Society's repos: https://github.com/TUHS https://github.com/TUHS (edit: although TUHS github presence is decidedly anemic!)
j1vms 9y ago
> (...) the direct challenge to the discourse of “free software” that Torvalds himself had never been interested in mounting. (...) “Free software because it works better” easily trumped “Free software because all software should be free”. I think Torvalds would decidedly have not been interested in that thesis. For example, while git has proven more popular and is probably now technically superior to its chief predecessor BitKeeper, Linus would have been content to continue using that proprietary tool had it not been for the reverse engineering "incident" of 2005 that led to git's conception. Linus appears driven instead by pragmatism, making use of what is practically available - proprietary or open - while building that which is not, should the path be clear in how to do so.
- paulddraper 9y ago
  ...and free software worked better. That's precisely the author's point: Torvalds interest in free software is practical, not ideological.
wscott 9y ago
It isn't clear from this link, but this is a chapter from "The Art of Unix Programming" by Eric Raymond
- vram22 9y ago
  Right. The taoup in the link does give a clue to those in the know, though.
enf 9y ago
The much more comprehensive history is Peter Salus's A Quarter Century of Unix, now online as page scans at http://wiki.tuhs.org/lib/exe/fetch.php?media=publications:qcu.pdf http://wiki.tuhs.org/lib/exe/fetch.php?media=publications:qc...
- acqq 9y ago
  And many details about BSD history in the first chapter of "The Design and Implementation of the 4.4BSD Operating System"
vram22 9y ago
I had seen this a while ago, a brief diagram of Unix history, on Éric Lévénez's site: https://www.levenez.com/unix/ https://www.levenez.com/unix/ The page also has some Unix history and related links.
joe_the_user 9y ago
The interesting thing about the second-system/third-system distinction is that it gives a strong impression that no one really knew exactly what an operating system should be until various examples were built. Arguably, that leaves open the possibility that further forms of OSes exist but aren't easily found due to the difficulty of putting together a system.
- moxious 9y ago
  So many layers are now built on top of the OS that it seems the most obvious way it will continue to grow is by gradually subsiding abstraction layers above that are so common, you'd never not want them. This has already happened with things like sound drivers, TCP/IP stacks, firewalling, etc. but will continue upward
  - paulryanrogers 9y ago
    There must be an upper limit though. Most of those things are invisible resources for users to do other work or play.
- Sir_Cmpwn 9y ago
  This is demonstrably true. The major OSes today are far from the forefront of innovative OS design.

147 points by rayascott 9y ago

*NIX, drives most of the world and is the reason why we exist the way we do today. It's also the reason why Google, Apple and other smaller outfits exist today.

macintux 9y ago
Agreed mostly, although I imagine VMS would have filled roughly the same ecological niche had UNIX not carried the day. Or maybe that's just optimism that something would have survived Microsoft's onslaught. The days when it looked like Windows was going to rule the world were quite dark.
- tyingq 9y ago
  That's an interesting path to think about. Minus UNIX, I'm curious where MVS, OS/400, VMS, MPE, DOS/Windows, etc, would have all played out.
  - Taniwha 9y ago
    well VMS still exists .... both as itself and as the underpinnings of WindowsNT (and modern windows)
    - ghaff 9y ago
      Many are still around to some degree. OS/400 is now IBM i. MVS is now z/OS (for IBM mainframes). OpenVMS as you say. Most of the operating systems that were originally written for minicomputers aren't radically different in fundamental design from Unix and Windows NT. My suspicion is that, absent Unix or something that followed a similar historical trajectory, these OSs would have had a longer run as non-legacy products, the landscape would have been even more fractured than it was with the Unix wars, and Windows would have become more dominant in the server space than it eventually became. The question I really don't know the answer to is whether, given the rise of the mainstream Internet, an open source operating system and infrastructure software necessarily would have followed. Or would the world look very very different.
    - bitwize 9y ago
      While it's true that Dave Cutler incorporated many ideas from VMS into Windows NT... they are very different beasts with very different code bases. Not even related in the same way that, say, Unix and Linux are.
  - dredmorbius 9y ago
    VM/CMS (another mainframe variant) may have played a stronger role. It in many aspects resembles Unix, far more than MVS.
    - skissane 9y ago
      What specific features of VM/CMS are you thinking of when you say that? If anything, I would say it is the other way around. The classic MVS filesystem is more hierarchical than the classic CMS filesystem (when I say "classic", I mean ignoring newer innovations such as SFS, BFS, HFS and zFS). The components of MVS dataset names resemble directories, even though they are mostly (but not entirely) just a naming convention. By contrast, the classic CMS filesystem (pre-SFS/BFS) has an essentially flat namespace on each minidisk – its file naming is closer to PC-DOS 1.0 than to Unix. So, even though both filesystems are quite remote from Unix, the MVS filesystem is a little bit closer to Unix's than the CMS filesystem is. Also, if you compare the support for multitasking on MVS to VM/CMS, I think you'll find that MVS is closer to Unix. A single MVS operating system image has multiple address spaces (processes) each containing one or more tasks (threads). By contrast, VM/CMS works by running a single-tasking operating system (CMS) in separate virtual machines on top of a hypervisor (although more recent CMS versions have added "application multitasking" which is roughly equivalent to threads). Although neither is exactly the same as the Unix model of processes and threads, MVS is much closer to Unix than VM/CMS is in this area. Given that, it is actually much easier to implement the Unix process model on top of MVS than on top of CMS, which I suspect is why MVS OpenEdition / z/OS Unix System Services comes with a full-featured fork() implementation (which passes the Unix conformance test suite), while CMS OpenExtensions' fork() isn't really fork() at all, it is actually vfork() pretending to be fork().
      - dredmorbius 9y ago
        I've not used CMS, though I have used, long ago, MVS. My understanding is that CMS followed in its genesis and development spirit a bit more of the Unix development mode. It was more popular among (at least some) users, and as I understood it, a bit of an ugly stepchild / embarrassment to IBM, who considered MVS the more buttoned down, business-oriented, product. This is based on some long-ago, hazy, second-hand accounts, mind.
- pjmlp 9y ago
  The desktop world has hardly changed thanks to the continuous GNU/Linux reboots. http://store.steampowered.com/hwsurvey http://store.steampowered.com/hwsurvey
  - ghaff 9y ago
    For the average person, Linux didn't and doesn't offer any compelling advantages for the desktop and had some potential disadvantages depending upon how it was used. Arguably, there are fewer good reasons to not use Linux any longer, but the desktop OS is increasingly irrelevant to most people anyway. Looking back, it's very unclear to me what commercially viable investments would have changed the overall trajectory of the desktop.
    - pjmlp 9y ago
      On iOS, ChromeOS, Android, the kernel is irrelevant. The fact that they run some variation of UNIX is a pyrrhic victory. Apple and Google can change the kernel to whatever they want, as long as they keep the iOS Kit APIs, Web APIs and Android Java Frameworks. Mostly only those writing device drivers would actually notice the difference. As an example where it is going, the new iOS 11 network APIs are not supported on BSD sockets, and Treble kind of moves Android into a pseudo micro-kernel model.
      - spamizbad 9y ago
        This line of thinking doesn't really make any sense. Both Apple and Google had plenty of options to chose from when laying the foundation for their operating system. Ultimately, in both cases, a *nix won out. Allowing BSD sockets inside the iOS Sandbox doesn't mean much of anything. Also, not clear on what Treble means here: Since its adoption in Oreo, Google has be demanding SoC vendors track closer to newer version of the Linux kernel. Source: https://www.xda-developers.com/google-mandating-linux-kernel-versions-android-oreo/ https://www.xda-developers.com/google-mandating-linux-kernel...
        pjmlp 9y ago
- ghaff 9y ago
  Absent Unix or a class of operating systems coming out of a similar tradition, the operating systems that came out of the minicomputer era (VMS, AOS/VS, OS/400, etc.) would presumably have maintained their roles to some degree absent Unixes displacing them. And it's very hard to see Windows NT not largely winning out in such a world. As you suggest, it was a close thing as it was and a lot of people thought Scott McNealy was tilting at windmills for not buying into Windows inevitability. Of course, that raises the question of what about open source in that world. I'm not sure it was in any sense inevitable that open source would have played out as it did. Although absent widespread open source adoption it is hard to see how the Internet would have grown as it did.

akerro 9y ago

If anyone is interested, I made a catalogue of UNIX-repos that I found online, I setup a gitlab account for all of it, with automated mirroring, here is the link https://gitlab.com/users/UNIX-history/projects https://gitlab.com/users/UNIX-history/projects If you know a repo I don't have here, let me know

macintux 9y ago
Not a repo, may be one somewhere though: http://www.nesssoftware.com/home/mwc/source.php http://www.nesssoftware.com/home/mwc/source.php (Considered buying Coherent way back in the day) There is an empty repo by this name in your project so I'm a bit confused whether this one is supposed to be included: https://github.com/dspinellis/unix-history-repo https://github.com/dspinellis/unix-history-repo
- akerro 9y ago
  Haha gitlab timeouted importing this repo and threw server error 500 on it, I'll do it manually.
- emmelaich 9y ago
  Diomidis Spinnelis' work is amazing. You can read about it here: https://www2.dmst.aueb.gr/dds/pubs/jrnl/2016-EMPSE-unix-history/html/unix-history.html https://www2.dmst.aueb.gr/dds/pubs/jrnl/2016-EMPSE-unix-hist... (link is from the github README)
emmelaich 9y ago
It would be nice to provide a description on that page of where you got each one. For instance, it's not clear whether it has any overlap with the Unix Heritage Society's repos: https://github.com/TUHS https://github.com/TUHS (edit: although TUHS github presence is decidedly anemic!)

j1vms 9y ago

> (...) the direct challenge to the discourse of “free software” that Torvalds himself had never been interested in mounting. (...) “Free software because it works better” easily trumped “Free software because all software should be free”. I think Torvalds would decidedly have not been interested in that thesis. For example, while git has proven more popular and is probably now technically superior to its chief predecessor BitKeeper, Linus would have been content to continue using that proprietary tool had it not been for the reverse engineering "incident" of 2005 that led to git's conception. Linus appears driven instead by pragmatism, making use of what is practically available - proprietary or open - while building that which is not, should the path be clear in how to do so.

paulddraper 9y ago
...and free software worked better. That's precisely the author's point: Torvalds interest in free software is practical, not ideological.

wscott 9y ago

It isn't clear from this link, but this is a chapter from "The Art of Unix Programming" by Eric Raymond

vram22 9y ago
Right. The taoup in the link does give a clue to those in the know, though.

enf 9y ago

The much more comprehensive history is Peter Salus's A Quarter Century of Unix, now online as page scans at http://wiki.tuhs.org/lib/exe/fetch.php?media=publications:qcu.pdf http://wiki.tuhs.org/lib/exe/fetch.php?media=publications:qc...

acqq 9y ago
And many details about BSD history in the first chapter of "The Design and Implementation of the 4.4BSD Operating System"

vram22 9y ago

I had seen this a while ago, a brief diagram of Unix history, on Éric Lévénez's site: https://www.levenez.com/unix/ https://www.levenez.com/unix/ The page also has some Unix history and related links.

joe_the_user 9y ago

The interesting thing about the second-system/third-system distinction is that it gives a strong impression that no one really knew exactly what an operating system should be until various examples were built. Arguably, that leaves open the possibility that further forms of OSes exist but aren't easily found due to the difficulty of putting together a system.

moxious 9y ago
So many layers are now built on top of the OS that it seems the most obvious way it will continue to grow is by gradually subsiding abstraction layers above that are so common, you'd never not want them. This has already happened with things like sound drivers, TCP/IP stacks, firewalling, etc. but will continue upward
- paulryanrogers 9y ago
  There must be an upper limit though. Most of those things are invisible resources for users to do other work or play.
Sir_Cmpwn 9y ago
This is demonstrably true. The major OSes today are far from the forefront of innovative OS design.